The transmission of the drive from the tractor power take-off through to the implement shaft which operates the two trenching tool shafts is almost exclusively by way of drive shafts of the cardan type, with double universal joints, mounted to the boom. The prior art embraces trench diggers, many of which are embodied basically as described above, that are operated by belt-or chain-drive transmissions.
Assuming overall dimension as par, the belt-driven type is capable of transmitting power of up to 60 or 7O HP; chain-driven types present the drawback of requiring forced lubrication.
Hydraulic power transmission, not yet adopted, involves difficulties of application, complicated technical requirements, and high costs.
The prior art stands in need of considerable improvement with regard to the option of replacing the conventional type of drive transmission between tractor and trench digger implements with a transmission that will not occasion the drawbacks found in the prior art.
From the foregoing, one may discern the need for a solution to the technical problem of embodying a drive system for transmission of power from a tractor power take-off to a trench digger input shaft which will be capable of transmitting higher power, up to 1OO HP and over, without belt slippage and without any requirement for forced lubrication, and in an economical manner.